EP1297600B1 - Portable battery pack system - Google Patents

Abstract

A keeper battery pack includes a housing incorporating an array of series-connected alkaline battery cells coupled to a cable extending outside the housing and terminating in a quick-connect connector plug adapted to plug into the charger port of a portable lead-acid battery power pack ofthe type used for jump-starting automotive vehicles. The keeper pack is portable and can maintain the charge on the battery power pack during extended periods of non-use, such as during storage, transportation and the like.

Description

Background

This application relates to battery power packs of the type used for jump-startingautomotive vehicles and, in particular, to lead-acid battery packs of the thin metal film type.The application relates in particular to charge maintenance in such battery power packs.

It is known to provide portable battery power packs for providing DC power inemergency situations and/or remote locations, such as for the purpose of jump-startingautomotive vehicle engines, the batteries of which have become discharged for some reason.Such battery power packs typically include lead-acid batteries of a capacity to provide DCvoltage and current sufficient for starting an automotive vehicle engine. Battery power packsare typically rechargeable and, since lead-acid batteries can become irreparably damaged iftheir voltage drops below a predetermined value, it is desirable that they be recharged aftereach use. A simple way of recharging such a battery power pack is to leave it connected tothe battery of the vehicle being jump-started so that, after the vehicle engine starts, the batterypower pack can be recharged by the vehicle charging system (alternator or generator). Priorbattery packs have also been provided with auxiliary charger ports so that they can beconnected to free-standing chargers when not connected to the vehicle.

However, lead-acid battery packs can also undergo a significant amount of self-dischargeduring extended periods of non-use, such as during storage, transportation or thelike. Accordingly, it is also known to provide a lead-acid battery power pack with a built-inset of alkaline batteries to provide a "keeper" charge current through a diode and a resistanceto make up for self discharge while "on the shelf" However, such built-in keeper charge systems add to the size, weight, complexity and overall cost of the battery power pack. Thus, thedesigner of the battery power pack is faced with a decision to reduce the size of the keeperbatteries to minimize size, weight, cost and the like, while also minimizing, the length of timethat the charge of the battery power pack can be maintained, or increasing the size of the keeperbatteries to lengthened the time that the charge can be maintained on the battery power pack, atthe expense of added size, cost, weight and the like.

U.S. 4,692,680 discloses a portable battery power pack including a group of series-connectedalkaline batteries for use in recharging an automotive battery by means of a cablewhich has at one end a plug which plugs into a socket on the battery pack and at the other end aplug which plugs into the cigarette lighter of the automotive vehicle. The pack delivers a highcharging current to the automotive battery in the range of from one-half ampere to four amperes.

Summary

The present invention has been defined in claim 1. Further developments andmodifications of claim 1 have been defined in the dependent claims.

An important aspect of the present invention is the possibility of maintainingthe charge in the battery power pack during extended periods of non-use, withoutadding to the size or weight of the battery power pack. Furthermore, the portablekeeper battery pack according to the present invention can be easily quick-coupledto and decoupled from the power battery pack, and is of simple and economicalconstruction.

Brief Description of the Drawings

For the purpose of facilitating an understanding of the subject matter soughtto be protected, there are illustrated in the accompanying drawings preferred embodiments thereof, from an inspection of which, when considered in connectionwith the following description, the subject matter sought to be protected, itsconstruction and operation, and many of its advantages should be readily understoodand appreciated.

FIG. 1 is a view, partially in front elevation and partially perspective, of asystem including a battery power pack and a keeper battery pack;

FIG. 2 is a partially schematic and partially functional block diagram of thecircuitry of the system of FIG. 1; and

FIG. 3 is a perspective view of an alternative form of keeper battery pack.

Detail Description

Referring to FIGS. 1 and 2, there is illustrated a battery pack system, generallydesignated by thenumeral 10, including a battery power pack 11 and akeeper batterypack 30. The battery power pack 11 may be of known construction and includes ahousing 12 connected bycables 13 to a pair ofconnector clamps 14, which can berespectively clamped onto the terminals of an automotive battery for purposes ofjump-starting an associated vehicle engine, in a known manner. The battery powerpack 11 is illustrated as disposed in an associatedcarrying pouch 15, both of whichmay be of the type disclosed in the copending U.S. application serial no. P-101,966,filed February 11, 2000 and entitled "Battery Pack and Protective Pouch Therefor."Thehousing 12 has acharger port 16 at one end thereof in the nature of a socket intowhich an associated charging device may be plugged. Thehousing 12 may beprovided with adisplay window 17 for an associated LCD display or the like coupled to suitable electronics in thehousing 12. Also disposed in thehousing 12 is a battery18 (FIG. 2) which may include one or more lead-acid cells, preferably of the thinmetal film type.

Referring in particular to FIG. 2, the battery power pack 11 also includes amicrocontroller 20 connected across the terminals of thebattery 18, and asuitablepower supply 21 also connected across thebattery terminals 18 and also connected tothemicrocontroller 20 for providing a suitable operating voltage thereto. Themicrocontroller 20 is also connected to asuitable display 22, which may be an LCDdisplay and may be disposed in use beneath thedisplay window 17 so as to beviewable therethrough. The terminals of thebattery 18 are connected tooutputterminals 25 and 26, respectively connected to thecables 13, and also connected toterminals of thecharger port 16, which may be coaxial.

Thekeeper battery pack 30 has ahousing 31 enclosing a plurality of series-connectedalkaline cells 33, sufficient in number to generate an output voltageapproximating a nominal normal operating voltage of thebattery 18, in this casebetween 12 and 13 volts. In the illustrated embodiment thecells 33 are C-cells or D-cells,each capable of generating 1.5 volts. Accordingly, nine such cells are connectedin series in thehousing 31 to produce an output voltage of 13.5 volts. Thus, thecells33 form a series array with end terminals respectively connected toconductors 36 and37, which form a cable 3 5 extending outside thehousing 31 and connected at its distalend to aplug connector 38, which may be of the coaxial type, and is adapted to beplugged into thecharger port 16 of the battery power pack 11. A current limitingresistor 39 is connected in series with thecells 33.

In operation, if the battery power pack 11 is to be "on the shelf" for anextended period of time, thekeeper pack 30 may be connected thereto by plugging theplug connector 38 into thechargerport 16, whereupon thekeeper battery pack 30 willprovide a continuous trickle or keeper charge to thebattery 18 to counteract the selfdischarge thereof, maintaining the nominal output voltage of thebattery 18 andpreventing its charge level from dropping to a dangerous level. The akaline cells areeasily replaceable when they become exhausted and thekeeper battery pack 30 maybe kept at the place of storage or transportation of the battery power pack 11 andconnected thereto only when needed.

Referring to FIG, 3, there is an alternativekeeper battery pack 30A which issimilar to thekeeper battery pack 30, wherefore like parts bear the same referencenumerals with the suffix "A." Thekeeper battery pack 30A has a size and shapewhich are different from those of thepack 30, being in this case substantiallyrectangular and of a suitable size for housing nine 1.5-volt cells of the "AA" size.While thekeeper battery pack 30A does not have the current capacity of thekeeperbattery pack 30, it has the advantage of small size, weight and expense. Otherwise,it works in the same manner described above for thekeeper battery pack 30.

From the foregoing it can be seen that there has been provided an improvedbattery pack system which permits charge maintenance of a lead-acid battery pack 11without affecting the size or weight thereof.

Claims (9)

1. A battery pack system comprising:

   an automotive battery of an associated vehicle;

   a battery power pack (11) which comprises:

   a first housing (12) including a battery (18), a charger port (16) and means (13, 14) forconnecting the battery power pack to the automotive battery for jump-starting theassociated vehicle; and

   a portable keeper battery pack (30) for providing a low-current keeper chargeto said battery power pack (11), which keeper battery pack (30) comprises:

   a second housing (31) separate from the first housing (12),

   an array of interconnected alkaline battery cells (33) disposed in the secondhousing (31),

   a current-limiting circuit (39) carried by the second housing (31) for limitingcurrent deliverable from the alkaline cells to a trickle level, and

   a cable (35) having an inner end connected to the array within the secondhousing (31) and an outer end disposed outside the second housing (31) and providedwith a quick-connect connector (38) removably electrically connectable to thecharger port (16) of the first housing (12).
2. The battery pack system of claim 1, wherein each of the battery cells (33) is a 1.5-volt cell.
3. The battery pack system of claim 2, wherein the array includes nine alkaline battery cells (33).
4. The battery pack system of claim 1, wherein each of the battery cells (33) is a C-cell.
5. The battery pack system of claim 1, wherein each of the battery cells (33) is a AA-cell.
6. The battery pack system of claim 1, wherein each of the battery cells (33) is a D-cell.
7. The battery pack system of claim 1, wherein the battery cells (33) are connected in series.
8. The battery pack system of claim 7, and wherein the current-limiting circuit includes aresistor (39) in series with the battery cells (33).
9. The battery pack system of claim 1, wherein the cable includes a pair of conductors (36,37) respectively connected to positive and negative terminals of the array.

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